In order to solve the problems of uneven size and difficult preparation methods of drugloaded microspheres, and to better apply them in clinical fields such as tumor treatment and cartilage repair. In this paper, drug-loaded polymer microspheres were prepared from polyvinyl alcohol, gelatin and sodium alginate by free radical polymerization, Schiff base reaction and calcium ion coordination reaction. It was characterized using instruments such as infrared spectroscopy, scanning electron microscopy, and ultraviolet-visible spectrophotometer. The results indicate that the three drug-loaded microspheres prepared in this article have uniform size, easy degradation of materials, and can meet the drug release requirements in cancer treatment.